1. Field of the Invention
This invention relates to information processing systems and in particular to an open network system and the management of system communication, therein. More particularly, it relates to fault management for the system and the protocols for exchanging network management information relating to tests for faults between system management and agent devices.
2. Description of the Prior Art
Systems management is the science of providing mechanisms and methods for the monitoring, control and co-ordination of the devices and resources within a network system. More simply, for an expansive computer system comprised of many elements, it concerns the ways that must be devised so that the elements can work together and communicate. The elements of the system are typically made by a number of different manufacturers so if the elements are to work together they must have a common means, accepted by the manufacturers, for communication and cooperation. The standards appropriate to the management of open communications and operations in a network are generally referred to as "Open Systems Interconnection" (OSI) standards.
The International Organization for Standardization (ISO) has been striving to set such common standards. These include specified procedures for carrying out necessary systems management activities. Such activities are generally grouped into five areas: fault management, configuration management, accounting management, performance management and security management. The subject matter of this invention generally concerns the activity of fault management.
The ISO has generally described systems management standards in a project paper entitled Information Processing Systems--Open Systems Interconnection--Systems Management: Overview, ISO/IEC JTC1/SC21/WG4 N571, July 1988. As described therein, the management functions of a conventional network management system are divided into managing processes and agent processes. The object of management is referred to as a "managed object." A managed object is a system resource that is subject to management, such as a layer entity, a connection or an item of physical communications equipment. A managing process has responsibility for a management activity. An agent process manages, at the request of a managing process, the associated managed objects. It is important to note that network management information relating to the managed object is exchanged between the managing process and the agent process.
For simplification purposes, hereafter a network managing apparatus performing a managing process will be referred to as a "manager" and a network managing apparatus performing an agent process will be referred to as an "agent".
The ISO has also generally described a protocol for fault management in a paper entitled Information Processing Systems--Open Systems Interconnection--Systems Management: Fault Management Working Document ISO/IEC JTC1/SC21 N3312, January, 1989. Much of the information necessary for fault management is derived from a systems function identified as confidence and diagnostic testing which provides for one user to direct another user to perform a test on a managed object to determine if it is capable of performing its service or to assist in diagnosis of a fault. This paper provides a model for the OSI environment in the operation of a test. The initiator of a test is referred to as a test conductor. It requests the execution of a test. A test performer executes the test. Test performers are considered to be managed objects and are sometimes referred to as "test objects." In a test whose execution is dispersed to involve more than one open system, separate test performers exist in each system. The test performer with whom the test conductor communicates is referred to as the primary test performer. The test performer with whom the primary test performer communicates is called the secondary test performer. The primary test performer includes a test request receiver which receives a test request from the test conductor, a test object comprising the test itself and the testing equipment, and a resource under test as the resource which is utilized in the test.